This is why you should also always use the appropriate needle. Faux leather and leather need a special leather needle. Really stretchy fabrics need a stretch needle, really thin fabrics a thin needle etc..
One thing I didnt see anyone else mention yet is paying attention to the direction of the fabric grain when cutting out your fabric. Learn to identify the direction and how it affects the drape and stretch of your garment. Wrong grain direction can cause curling seams and awkward draping. This is the number one mistake I made as a newbie.
Another thing to keep in mind is fusible interfacing, itll be your best friend when making collars, button plackets, or just in general when working with thin and flimsy fabrics. It adds support and structure to a garment.
Choosing the correct type of fabroc for your project is also super important but I still kinda suck at it so I wont give any advice on that lol.